Multiple antenna



Aug. 10 1926.' 1,595 ,l66

O. SCHELLER 'MULTIPLE ANTENNA Filed Feb. 5, 1925 Vil Aug. lil, 1926.

UNITED STA'ES rn'reur series.

OTTO SCHELLER, OF BERLIN-GEOSS-LCHTERFELDE, GERMAN?, ASSIGHOE TO C.

LORENZ AKTIENGESELLSCHAFT, OF BERLIN-TElVIPELI-IOF, GERMANY.

MULTIPLE AN'I'EIJNA.`

Application filed February 3, 1925, Serial Ne. 6,593, and in Germany September 11, 1923.'

My invention relates to aerials 'for use in" systems or" radio communication and has :tor its object to increase their radiating power.

All the transmitters of radiotelegraphy hitherto constructed have a very low eiiiciency owing to the fact that only sa small portion of the 'energy converted to oscillations in the aerial is utilized for the purpose 'of radiation. A portion does not leave the aerial system and is gradually damped by its ohmic resistance. Of an energy really radiated only a small portion is radiated to a suflicient distance required for the 'working of the transmitter.

The manner of Viewing things hitherto as to the action at a distance of a straight wire does not lead to an idea, which allows the arrangement to 'be efi'ectively accomplshed; The ideas which Maxwell has developed in the last century about the propagation or" electrical oscillations, have not yet been taken up by technics, which would be necessary to utilize them tully for the present task of improving radiation.

In space telegraphy the action at a distance must be imagined to be caused in the following way:

As the displacement currents generate in the dielectric magnetic fields in the same way as Currents do in conductors, and as further in a 'Jreely oscillating circuit consisting of capacity and self-inductance, the clisplacement currents in the capacity must be referring to time in phase coincidence with the currents in the conductor, the magnetic field of an oscillation crcuit can only be such a one as can be produced by closed current lines. This law must be valid 'or all the current circuits, for closed ones as well as ;tor open ones. The displacement currents'must be in phase coincidence with the line-currents, since at the times when the whole energy is in the condenser, both current-s, displacement currents and line-currents, must be Zero. The form of the condenser cannot have any influence upon it. i

The prior conceptionot the action at a distance of a conductor, e. g. a straight wre, can no more be maintained; the considerations about the action at a distance started from the magnetic field of a straight limited condvctor, which foritself cannot exist and cannot be realized therefore. Since all the lines of current occur only as closed paths, there' are in reality .only fields such as are generated by such closed current circuits.

An action at a distance is only imaginable, it lines of current of reversed direction have such a great distance that the fields of the single line ot current interfere with each ot ler so that they do not neutralize each other, but sum each other, if possible. In the normal aerial systems hitherto-used the action at a distance is done by at least some *lines of the displacement current running at a large distance from the conductor, thereby an action of interference being made between the field of these lines of current and the current in the conductorf I may essentially improve radiation-according to my proposal dating from the year lQll-by giving the conductor a diameter. as large as possible, by which more lines of force are forced outwards, so that more lines of current take part in the inter- 'ference action. Thus by increasing the diameter I can increase radiation ncarly at my will, I do not yet obtain, however, the maximum of radiation which is possible at the actual diameter of the aerial syster In order to obtain this maximum radiation it is necessary that as 'few displacement currents as possible run in the neighbourhood of the conductor. I obtain that-just as in the forlner proposal-by subdividing the conductor into many single lines and by making all the single conductors oscillate in phase, but by distributing' the single lines in such a way that as lar as possible no lines of force can circulate from the upper end of the lines between the single conductors but that, if possible, all the dsplacement current lines are forced outwards. For this purpose the lines individually tuned ac- 9 cording to the density of electric fields generated by them, are dis ributed over the whole area covered by the a'erial. For the first approximation it will be sutficient to distribute the conductors upon a ring which is most favourably {ed with' energy from the centre. Since all the fields oscillate in phase, they generate fields of the same sense. Thereby the back running lines of current of the displaced currents find their way between the conductors barred, andthese are forced outwards. By the form of the' area I can prefer the radiation in a certain direction which is well known.

.Bythe dense' arrangement of the different radiators I obtain in the same time that the earth area below the whole radiator system is covered with the earthing devices somewhat equally, so that great densities of earth-Currents are avoided and in the same time the development oi displacemcnt currents in contrary direction within the aerial system is effectively counteracted against.

By way of example oi: my invention the accompanying drawings show an aerial which mainly is carried by one single high mast, and which is to radi-ate in all directions uniformly.

Fig. l shows the elevation Fig. 2 half the plan.

As the height of the aerial decreases outwards the vertical lines a b, c, (Z are arranged closer together. When A is the highest point of the line a, the tuning of b, c, d can be eiected in such a manner that reflection ot the energy oscillating in' these lines takeplace in A. Correspondingly, when B marks the junction point of c at th highest point of b, C the junction point of (Z at the highest point of e, on the other hand the tuning of cnay also be effected in such a way that reflection takes place at point B, that of (Z so that reflection takes place at C. The exact position of the reflection points is not essential for the utilization of my invention provided they do not lie on the single lines a, Z), c and d, for in these lines all the currents are to oscillat at the same time in the same direction. e having the smallest Capacity, here the wattless Currents will be smallest, practically a carri'es only the whole watt current. Therefore the whole transmitting set may be made smaller. As the distance of the upper part of (J to the earth is less than say of b, there is a risk that considerably more lines ot forc run to earth between c and d. Therefore the intervals between c and d` and between the single lines of (l (Fig. 2) are chosen smaller than in the middle of the system. In case the uniformity of radiation at an aerial system according to Big. 2 should not be sufiicient, the number otthe lines going radially from the middl of the arrangenent and directed downwards such as AD (D being the highest point of ci) can beincreased as may be required.

What. I claim is:

l. A multiple antenna structure comprising in combination a plurality of earthed conductors a source of high frequency current for exciting said conductors in like time phase, means for neutra-lzing substantially 'all electric* lines within the antenna structure and torcin-g them outside said structure by suitably dinensioni-ng the earthel conduetors and distrihuting them in proporton to; the strengthof the electric generated thereby' for ircreasing radiation of said source and reducing losses therein.

2. in a multiple antenna structure the combination of a central earthed conductor, a high frequency source. for energizing said conductor a plurality of earthed conductors arranged around and all united with said central conductor said plurality of earthed conductors having height-s decreasing with the distance from said central conductor and with their respective distances one froni another proportioned according to the density of the electric lines of force generated therein by them.

3. In a multiple antenna structure, the combination ot' a central earthed conductor, a high trequency source for exciting said conductor a plurality' of concentrie rows of cart led conductors united all at their upper ende with said central conductor, 'each row of said last mentione'd conductors decreasing in height in an outward direction and each concentric row having 'said plurality of conductors decreasing in spaced relationship in proporton to the height thereof.

e. A multiple antenna structure comprising in ccinbination a central vertical'ly disposed grounded conductor, a source of high trequency oscillations connected with said con'ductor, a plurality of tuned conductors positioned in radial' lines with respect to said central conductor, said last mentioned conductors being spaced from each other at varying distances and each having varying heights with the upper eXtremities thereof connected with the upper extremity of said central conductor for increasng the radiation of said source and reducing the losses in said antenna structure.

5. A multiple antenna structure comprising in combination a central vertically disposed conductor', a high frequency source tor exciting said conductor, a plurality of vertically disposed conductors positoned in radial lines with respect to said central conductor, said plurality of conductors being spaced one from another at varying distances and each varyi'ng in height and having the extremities thereof connected with the extreinity of said central conductor for' increasing the radiation of said source' and re'ducing the l'osses in said antenna structure.

6. A multiple antenna structure compris'- ing in combination a vertical centrall 'y disposed conductor, a source of'high frequency current for exciting said conductor, a plurality of vertically extending conductors positioned in raclial: lines; on either-siide ofisaid central Vertical conchctorr, said.. plurality *of conductors* being-space& one' fron'r another and from said' cemral .cndructor over" tereni; distances ancteacho'ffsa i `hirality of* conduetors having: dierent heights with respect to said central conductor, With the upper extrentes thereof connected With the upper extremty of said central conductor for increasing the radation from said source and reducng losses in said antenna structure.

7. A multiple antenna structure comprising in combination a central Vertcally ,disposed conductor, a plurality of vertically disposed conductors arranged in radal lines With respect to said central conductor and in concentrc circles around said central conductor With the distances between the concentrc circles in Which said plurality of Vertically dsposed conductors are arranged Varyng one from another and With the heghts of -said pluralty of conductors varying one from another and connected at their upper extremities With the upper extremity of said central conductor for ncreasing the radation from said antenna structure and reducing electrical losses therein. r

8. A multiple antenna structure comprsposte sides of said centrally dsposed conductor, said plurality oi' conductors being arranged n concentric crcles wth the dstances between said concentric circles grow-- ing smaller as said plurality of conduct-ors extend outWardly and With the heghts of said pluralty of conductors growng smaller as said plurality of conductors extend out- Wardly, With connections extending from the extremity of said centrally disposed conductor in a downward direction to the extrenties of each of said pluralit-y of conductors for increasng the radaton of said antenna structure and reducng the losses therein.

In testimony Whereof I have afiixed my ignature.

OTTQ SCHELLER. 

